It is well-known that internal combustion engines exhibit degradation in performance and/or reliability over time as wear occurs on the moving portions of the engine. Without maintenance, all engines will eventually fail after some period of use. Additionally, it has long been recognized that preventative maintenance (servicing the engine before it fails) can substantially reduce the overall cost of operating an engine. This is because the pieces of an engine work in concert with one another, and failure of one piece can lead directly to failure of other pieces. Replacing the pieces that are most likely to fail before such failure occurs can therefore substantially lower engine maintenance costs. Obviously, it is desirable to be able to predict when such failure is likely to occur so that preventative maintenance can be performed beforehand, but not so early that a significant portion of the replaced part's useful life is not utilized.
For applications where the engine is in a commercial vehicle, such as a diesel truck, it is also desirable to be able to predict engine failure in advance in order to minimize productive downtime of the vehicle. Such downtime can be very expensive to the vehicle owner due to lost revenue in addition to the repair cost.
Most modern engines are controlled by an electronic engine control module (ECM) that has access to the readings of various sensors placed around the engine, and it is known in the prior art to cause the ECM to periodically store selected sensor data in order to track the "health" of the engine versus time. Such data can be very useful in predicting mechanical failures in advance of a breakdown so that preventative maintenance can be performed. Such data can also be valuable to instill buyer confidence in the health of an engine when it is sold on the used market.
However, the ability to forecast the need for engine servicing and the ability to troubleshoot engine failure by looking at historical engine sensor data can be hampered if the data is not collected in a controlled manner. There is therefore a need for an engine control module that is operative to collect and store engine data in a consistent manner, such that all of the data stored is relevant to the rest of the stored data, thereby making historical data comparisons useful. The present invention is directed toward meeting this need.